Eco-friendly Arsenic remediation using modified rice husk and banana peel: a biosorption based approach with plant...

Access to clean drinking water is essential for healthy lifestyle. Arsenic (As) contamination in drinking water causes significant health risks. The current study explores an eco-friendly and sustainable solution for As sequestration by plant-based agrowaste immobilized sodium alginate beads. Rice husk and banana peel beads were assessed for biosorption efficiency using atomic absorption spectroscopy (AAS). Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analyzed the changes in surface morphology after the biosorption process. The safety of the post-adsorbed water for drinking was evaluated using Allium cepa as plant test model. Root growth was monitored for 14 days, while cytotoxic effects were assessed via chromosomal aberrations and mitotic index (MI). The results revealed excellent biosorption efficiency of the two beads; the rice husk beads removed 53.35% whereas banana peel beads removed 58.11% of As from an initial concentration of 400 µg/L. For each 300 mL of As solution, 10 biosorbent beads of 50-70 mg dry weight were used. SEM images and EDX spectrographs revealed significant changes on the surface morphology and elemental composition following the biosorption process. Only As exposure reduced the root growth (1.56 ± 0.29 cm), increased the chromosomal aberration (17.30 ± 2.00%) and reduced the mitotic index to 1.39 ± 0.16%. The effects could be reversed after exposure with post-adsorbed As-removed water treated with biosorbent beads. Comet assay performed after 48 h revealed that increased tail DNA content and Damage Index (DI) as observed in As-exposed roots also reverted to normal levels upon growth in the post-adsorbed solution. Therefore, Sod. alginate beads coupled with modified agricultural waste may act as a possible eco-friendly and sustainable mode of As sequestration from drinking water that is suitable for plant growth.